Method and apparatus for the introduction of auxiliary separating fluid in fluid sample analyses means

ABSTRACT

New and improved means for the introduction of an auxiliary separating fluid to fluid sample analysis means are provided and comprise means to introduce a series of spaced bubbles of said separating fluid to a stream of successive fluid sample portions flowing in a fluid sample analysis means conduits substantially at the respective beginning and end of each of said fluid sample portions to delineate the same, means to introduce a series of substantially phased spaced bubbles of said separating fluid to another fluid stream flowing in another fluid sample analysis means conduit, and means to flow parts, at least, of at least one of said series of separating fluid bubbles through the flow cell of said fluid sample analysis means.

United States Patent [72] Inventors Jack lsreeli 3,241,432 3/1966 Skeggs etal. .4 23/253 X Mamaroneek; 3,241,923 3/1966 Ferrari .1 23/253 X Aaron Karel, Brooklyn; Richard H. 3,306,229 2/1967 Smythe 23/253 UX Helium, Flushing, all of, N.Y. 3,418,053 12/1968 Pelavin..... 23/253 UX [21] AppL No. 854,337 3,422,667 1/1969 Hrdina 23/253 UX [22] Filed July 25, 1969 3,484,170 12/1969 Smythe 73/433 X [45] Patented Aug. 24, 1971 [73] Assignee Inhalers-CW6 jzzfg f fg'ggg ks arrywwn,

54 METHOD AND APPARATUS FOR THE I 1 INTRODUCTION or my SEPARA-HNG ABSTRA C T: New and improved means for the introduction FLUID [N FLUID SAMPLE ANALYSES MEANS of an auatgia'y segaratlng fluid tczguitd analgsis mean? 20 3mm! are prov: e an comprise me o m r uce series 0 spaced bubbles of said separating fluid to a stream of succes- [52] [1.8.61 73/423 A, sive fl id sampk portions fl i in a fl id Samp|e analysis 23/253 means conduits substantially at the respective beginning and [51] lnLCl G011: 1/10 and f each f said fl id 53mph portions to delineate the same means {0 introduce a series of ubstantially 23/253 2923 210/32] spaced bubbles of said separating fluid to another fluid stream flowing in another fluid sample analysis means conduit, and [56] Rdem cued means to flow parts, at least, of at least one of said series of UNITED STATES PATENTS separating fluid bubbles through the flow cell of said fluid 3,134,263 5/1964 DeJong 73/423 sample analysis means.

36 120 38 l T v L 4O :02 lacs l i l l H WWl l m l l i m le rs -w w l 5 3 V 1 TO 37 6 mos PATENTEU AUB24|9T| SHEU 2 OF 3 INVENTORS JACK ISREELI ARON KASSEL ICHARD H. HEIMANN BY M [gut ATTORNEY METHOD AND APPARATUS FOR THE INTRODUCTION OF AUXILIARY SEPARATING FLUID IN FLUID SAMPLE ANALYSES MEANS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to new and improved auxiliary separating fluid introduction method and apparatus for use in automatic fluid sample analysis means.

2. Description of the Prior Art and Problem to be Solved Automatic, sequentially operable fluid sample analysis means in the nature, for example, of those shown and described in US. Pat. No. 3,134,263 issued May 26, I964 to E. B. M. DeJong, and 3,24l,432 issued Mar. 22, I966 to Leonard T. Skeggs, respectively, are known to include fluid sample pump means and colorimeter means having a flow cell through which the appropriately treated fluid samples are flowed for colorimetric analysis thereof. Such prior art analysis means additionally include means formed by said pump means to add a separating fluid such as air to a fluid sample portion stream to segmentize the same and promote essential fluid sample analysis means cleansing and fluid sample color producing reagent mixing, as well as debubbler means which are effective to remove all of said separating fluid from said fluid sample portion stream prior to the flow thereof through said flow cell. As a result, it may be understood that the problem arises of appropriate cleansing of said flow cell to prevent contamination of a said fluid sample portion by the residue of a preceding fluid sample portion. As shown and described in detail in said US. Pat. No. 3,134,263, this problem is solved primarily by the introduction of a suitable wash liquid segment between adjacent sample portions and the flow thereof through the flow cell to cleanse the latter in generally satisfactory manner.

Further, development work on such fluid sample analysis means has, however, resulted in significantly advanced versions thereof which are operable at substantially increased fluid sample portion analysis rates, but with substantially decreased fluid sample portion volumes and correspondingly decreased fluid sample portion flow rates. As a result of the substantially increased fluid sample portion analysis rates, it may be understood that substantially decreased times are available for the analysis of each sample portion, and that this factor, combined with the substantially decreased fluid sample portion flow rates, renders impossible the requisite, suitable cleansing of the analysis means flow cell through reliance on a wash liquid segment alone. This is to say that the passage of at least one segment or bubble of a suitable separating fluid through the said flow cell intermediate the passage of succeeding fluid sample portions therethrough has become essential to effect proper cleansing of the said flow cell within the available time. Despite these considerations, however, it is still necessary to remove the separating fluid which segments the respective fluid sample portions to enable meaningful colorimetric analysis thereof.

OBJECTS OF THE INVENTION It is, accordingly, an object of this invention to provide new and improved method and apparatus for the introduction of an auxiliary separating fluid into the fluid sample streams of automatic colorimetric fluid sample analysis means, and the flow of a portion, at least, of said auxiliary separating fluid through the flow cell of such analysis means to effect satisfactory, intersample cleansing of said flow cell.

Another object of this invention is the provision of method and apparatus as above which are operative to introduce said auxiliary separating fluid into discrete flow paths of such analysis means in substantially perfect phase relationship.

Another object of this invention is the provision of apparatus as above which requires the use of only readily available components of proven dependability in the fabrication thereof and insures long periods of satisfactory, maintenancefree operation thereof.

A further object of this invention is the provision of method and apparatus as above which are particularly adaptable for use in conjunction with advanced versions of automatic analysis means as shown and described in US. Pat. Nos. 3, l 34,263 and 3,241,432.

SUMMARY OF THE INVENTION As disclosed herein, the new and improved method and apparatus for the introduction of auxiliary separating fluid are useful in conjunction with fluid sample analysis means which provide for the concomitant flow of a series of fluid-segmented fluid sample portions through one analysis means conduit, and a fluid-segmented liquid in the nature of a recipient stream through another analysis means conduit. In a first form, the method and apparatus of the invention provide for the introduction of an auxiliary separation fluid bubble at the beginning and end of each of said fluid sample portions, the detection of each of said bubbles, and the subsequent introduction of a substantially correspondingly sized and located auxiliary separating fluid bubble in said recipient stream. Also included in the fluid sample analysis means are debubbler means which are effective to remove all of said segmenting fluid and parts, only, of said auxiliary separating fluids, leaving the remainders of the latter to flow through the fluid sample analysis means flow cells for the requisite intersample cleansing thereof. In a second form, the method and apparatus provide for the substantially concomitant introduction of said auxiliary separating fluids at corresponding locations in said fluid sample analysis means conduits.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. IA and IB show a generally schematic flow diagram of fluid sample analysis means incorporating a first form of the new and improved auxiliary separating fluid introduction means of the invention; and

FIG. 2 is a generally schematic flow diagram of the same fluid sample analysis means incorporating a second form of the new and improved auxiliary separating fluid introduction means of the invention.

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 1 of the drawings, fluid analysis means incorporating a first form of the new and improved auxiliary separating fluid introduction apparatus constructed and operative in accordance with the teachings of this invention may, for example, take the general form of those shown and described in US. Pat. No. 3,134,263 issued May 26, I964 to E. B. M. DeJong, and US. Pat. 3,24l,432 issued Mar. 22, I966 to Leonard T. Skeggs et al., respectively, and, as depicted in FIGS. IA and 18 may be understood to be somewhat simplified in that only those portions thereof which are considered necessary to the full disclosure of this invention are specifically shown and described.

As depicted, the fluid sample analysis means comprise a sample supply device I2 which, as disclosed in said US. Pat. No. 3,134,263, includes a turntable 14 upon which are disposed a plurality of fluid sample containers l6, and adjacent to which is disposed a wash liquid receptacle 18.

Sample offtake means are indicated at 20 and comprise a sample offiake tube 22 which is movable from the depicted position thereof wherein the tube inlet end is immersed in a sample container 16, to another position thereof wherein the said inlet end is immersed in the wash liquid receptacle 18. The turntable I4 is intermittently rotatable, under the control of nonillustrated sample supply device drive means, to successively present each of the fluid sample containers 16 to the sample offtake means 20, while the latter are operable, under the control of said sample supply device drive means, to alternately position the inlet end of the ofltake tube 22 in a thusly presented fluid sample container 16 and the wash liquid receptacle 18.

Peristaltic pump means are indicated generally at 24 and, as disclosed in said U.S. Pat. No. 3,241,432, may be understood to comprise a series of nonillustrated pump rollers which are operable as indicated by pump drive means 25 to compress or occlude compressible pump tubes 26, 28, 29, 30, 31 and 32 longitudinally thereof in the direction from left to right as seen in H6. 1 to pump fluids therethrough in the said direction.

As arranged, it may be understood that concomitant operation of the sample supply means 12 and the peristaltic pump means 24 will be efiective to supply a series of different sample portions, as indicated at 5,, S, and S from successive ones of the sample containers 16 to a connected conduit 34', and that the said sample portions will be spaced, as shown, at both the upstream and downstream ends thereof by a segment of air, indicated as A, which is aspirated through offtake tube 20 as the latter is moved through the ambient air from a sample container 16 to the wash liquid receptacle 18, a segment of wash liquid, indicated as W, which is aspirated through offiake tube 22 when the inlet end thereof is immersed in the said wash liquid receptacle, and another segment of air A which is aspirated through said offtake tube as the latter is again moved through the ambient air from the said wash liquid receptacle to the next presented sample container 16.

A conduit 36 connects the outlet end of compressible pump tube 26 to the inlet port of a remotely controllable, two-way valve 38, while a branch conduit 40 connects one outlet port of the said valve to conduit 34. The other outlet port of the two-way valve 38 communicates as indicated with the atmosphere.

A conduit 42 is connected to the outlet end of compressible pump tube 30, while the inlet end of said compressible pump tube is immersed, as indicated, in a container 124 of a suitable fluid, whereby may be understood that operation of the peristaltic pump means 24 results in supply of a stream of said fluid, indicated as R, to conduit 42.

A conduit 44 connects the outlet end of compressible pump tube 32 to the inlet port of a remotely controllable, two-way valve 46, while a branch conduit 48 connects one outlet port of valve 46 to conduit 42. The other outlet port of valve 46 communicates as indicated, with the atmosphere.

Valve 38 is arranged so that, in one position the same is effective to connect conduits 36 and 40 and, in the other position, to disconnect these conduits and vent conduit 36, to atmosphere. ln like manner, valve 46 is arranged so that, in one position conduits 44 and 48 are connected while, in the other position these conduits will be disconnected and conduit 44, is vented to atmosphere.

A branch conduit connects the outlet end of compressible pump tube 29 to the conduit 34 upstream of the connection of conduit therewith. A branch conduit 37 connects the outlet end of compressible pump tube 31 to the conduit 42 upstream of the connection of conduit 48 therewith.

With the respective conduits 35 and 37 connected, as described, it may be understood that operation of the peristaltic pump means will be eflective to continually supply pressurized air to each of conduits 34 and 42. More specifically, and with regard to conduit 34, it may be understood that this pressurized air will be effective to segmentize the respective fluid sample portions and wash liquid segments flowing therethrough by the formation of segmenting air bubbles AS and AW, as indicated. In like manner and with regard to conduit 37, it may be understood that this pressurized air will be effective to segmentize the fluid stream R flowing therethrough by the formation of segmenting air bubbles AR, as indicated.

A dialyzer which may, for example, take the form of that shown and described in said U.S. Pat. No. 3,241,432, is indicated at 50 and may be understood to comprise a donor stream side 52 and a recipient stream side 54. The conduit 34 is connected, as shown, to the inlet of the donor stream side 52 and the conduit 42 is connected as shown to the inlet of the recipient stream side 54 of the dialyzer 50.

Debubbler means which may, for example, take the form of those shown and described in said U.S. Pat. No. 3,24l,432,

are indicated at 56, and a conduit 58 extends as shown to connect the outlet of the donor stream side 52 to the inlet of the said debubbler means. Debubbler means of like construction are indicated at 60, and a conduit 62 extends as shown to connect the outlet of the recipient stream side 54 to the inlet of the debubbler means 60.

Colorimeters which may, for example, take the form of those shown and described in said U.S. Pat. No. 3,24l,432 are indicated in dashed lines at 64 and 66, respectively, and include flow cells 68 and 70 having respective sight passages 72 and 74 formed therein. A conduit 76 connects the outlet of debubbler means 56 to the inlet of flow cell 68, while a conduit 78 connects the outlet of debubbler means 60 to the inlet offlow cell 70.

Further included in colorimeter 64 are a light source 80 and photoelectric detector means 82 disposed as shown adjacent opposite extremities of the flow cell sight passage 72 to enable the colorimetric analysis of fluids flowing therethrough in a manner known to be well understood by those skilled in the art. In like manner, colorimeter 66 includes a light source 84 and photoelectric detector means 86 disposed and operative, as described above, with regard to sight passage 74 of flow cell 70.

Stepping switch means 88, and strip chart recorder means 90, each of which may, for example, take the form of those shown and described in said U.S. Pat. No. 3,241,432, are connected as shown to the respective photoelectric detector means outputs by leads 92 and 94, respectively to provide for the sequential recording on recorder chart 98 of the results of the colorimetric analyses performed by colorimeters 64 and 66, again in a manner known to be well understood by those skilled in this art.

Auxiliary separating fluid detecting means are indicated generally at 100 and, as depicted, take the form of an infrared energy source 102 and infrared filter means 104 disposed as shown to one side of conduit 34-h being understood that conduit 34 is constructed from a material with good infrared energy transmission characteristics in the nature of clear glass-and infrared detector means 106 disposed as shown to the opposite side of said conduit in substantial alignment with infrared energy source 102.

A differential amplifier is indicated at 108 and is connected as shown to the output side of the detector means 106 by lead 110, while a lead 112 connects the output side of said dif ferential amplifier to delay timer means 114.

Valve operating means which may, for example, take the form of a valve operating solenoid, to operate valve means 46, are indicated at 116 and are connected as shown to the output side ofthe delay timer means 114 by lead 118.

The auxiliary separating fluid detecting means 100 are operative upon detection of an auxiliary separating fluid or air bubble ASD to start delay timer means 114 which, after the expiration of a predetermined time period, operates valve 46, through valve operating solenoid 116, to connect conduits 44 and 48, so as to supply an auxiliary separating fluid into the recipient stream along conduit 42 for a time period sufiicient to form an air bubble ASR therein of substantially the same extent as the detected air bubble ASD. More specifically, it may be understood that differential amplifier means 108 are operative to provide an output on lead 112 effective to activate or start delay timer means 114 only when the output on lead from detector means 106 exceeds a predetermined threshold, and said detecting means are in turn arranged to provide such threshold exceeding output only upon the sensing thereby of an auxiliary separating fluid or air bubble of the extent of the auxiliary air bubble ASD.

Referring again to valve means 38, it may be seen that the same include valve operating means 120 which may, for example, take the form of a valve operating solenoid, and that the latter are connected as indicated by lead 122 to the pump drive means 25, to provide for the operation of the said valve means in substantial synchronization with the operation of the said pump drive means. More specifically, it may be understood that pump drive means 25 and valve operating means 120 are arranged and the latter programmed to operate valve 38, so as to connect conduits 36 and 40 for a predetermined time period and supply an auxiliary separating fluid or air bubble ASD, of predetermined extent as determined by said time period, to the donor stream flowing along conduit 34 as each of the downstream and upstream ends of the fluid sample portions 5,, 8,, 8,, etc. reach the juncture of conduit 40 and conduit 34.

Referring now to the form of the auxiliary separating fluid introduction system of the invention depicted in FIG. 2, it may be seen that the same is substantially similar to that of FIGS. 1A and 1B and like reference numerals are utilized to identify like system components. In the form of the system of FIG. 2, however, it may be seen that the auxiliary separating fluid or air bubble detection means 100 are eliminated and that the valve 46 is operated, as indicated by lead 124, from the same pump drive means source 25 as is the valve 38, and in synchronism therewith. in addition, it may be seen that the juncture of conduit 48 and conduit 42 is moved into substantial alignment with the juncture of conduit 40 and conduit 34 whereby the auxiliary separating fluid or air bubbles ASD and ASR will be introduced to said donor and recipient stream conduits 42 and 34 at substantially corresponding locations in the respective donor and recipient streams flowing therethrough.

OPERATION in operation of the invention form of FIGS. 1A and 1B for use, for example, in the automatic sequential analysis of blood serum samples in advanced versions of the fluid sample analysis means as disclosed in said US. Pat. No. 3,134,263 and 3,24I,432, wherein extremely small blood serum sample portions in the order of 0.1 or 1.2 ml. are supplied to the analysis means at extremely high sampling rates in the order of 300 per hour. in such event, each of fluid sample containers 16 would be filled with a different blood serum sample, the wash liquid receptacle l8 filled with a suitable wash liquid in the nature of water of clinical purity, flask 124 would be filled with a liquid in the nature of water of clinical purity for the aspiration thereof through compressible pump tube 30 to form a recipient stream, while the respective inlet ends of compressible pump tubes 26, 29, 31 and 32 would be left open to atmosphere-although suitable, nonillustrated air filter means could, of course, be operatively disposed therein-to provide for the aspiration of air therethrough upon operation of the peristaltic pump means 24.

If required to enable the suitable provision of the respective auxiliary air bubbles ASR and ASD-which are, of course, of greater volume than the respective segmenting air bubbles AW, AS and ARthe respective internal diameters of the compressible pump tubes 26 and 32 may be made larger than the respective internal diameters of the compressible pump tubes 28, 29, 30 and 31, so as to increase the fluid-flow rate through the former upon operation of the peristaltic pump means 24 and insure the provision of sufficient pressurized air to valve means 38 and 46 for the formation, on demand, of the said auxiliary air bubbles in the respective donor stream conduit 34 and recipient stream conduit 42.

In addition, it may be understood that pump drive means 25, or suitable timer means which may be operatively associated therewith, would be programmed to operate valve means 38 to connect conduits 36 and 40 for a time period predetermined to provide an auxiliary air bubble ASD of predetermined extent to the donor stream every time a leading or trailing edge of a fluid sample portion S arrives at the juncture of conduits 40 and 34, while delay timer means 1l4 would be programmed to provide, through operation of valve means 46, an auxiliary air bubble ASR of substantially the same predetermined extent in response to each starting or activation thereof. Too, the width of the transmission path of infrared energy between energy source 102 and detector means 106 will be established so that only an auxiliary air bubble ASD or, more significantly, not an intrawash liquid segment air bubble AW or an intrasample air bubble AS, will be effective to enable an output from detector I06 on lead exceeding the threshold level of differential amplifier 108.

Assuming steady-state operational conditions to have been reached, it may be understood that as the downstream side of the air segmented sample portion S2 reaches the juncture of conduits 40 and 34, the pump drive means 25 will be operative to operate valve means 38 to connect conduits 36 and 40 for a predetermined period of time to introduce an auxiliary air bubble to the recipient stream for combination with the air bubble A to form the auxiliary air bubble as indicated at ASD,. At the expiration of this predetermined time period, it may be understood that valve means 38 will be operated to disconnect conduits 36 and 40 and vent conduit 36 to atmosphere, so as to discontinue the supply of air to conduit 34 while enabling the necessary venting to atmosphere of the compressed air being constantly supplied thereto by operation of pump means 24 and attendant compression of pump tube Each auxiliary air bubble, thus formed, will be flowed by the flow of the donor stream to the position thereof indicated at ASD, in FIG. 1A whereby the same will occupy that portion of the donor stream conduit 34 which lies in the transmission path of the infrared energy source 102 to detector means 106.

As a result, it may be understood that the level of infrared energy transmitted between said source and detector will be sharply increased-the infrared energy transmission characteristics of air being, of course, much greater than those of either the blood serum samples or wash liquid-whereby the output from detector means 106 on lead 110 will exceed the predetermined threshold level of differential amplifier 108 to result in the starting or activation of the delay timer means l 14 thereby.

After the expiration of a predetermined period of time which may, of course, be understood to substantially coincide with the arrival of an auxiliary air bubble ASD at the location in donor conduit 34 indicated at ASD,, delay timer means 114 will be effective to operate valve means 46 to connect conduits 44 and 48 for a period of time sufficient to introduce an auxiliary air bubble ASR into the recipient stream flowing in conduit 44, and it is made particularly clear that the said auxiliary air bubble ASR will be of substantially the same extent as the relevant auxiliary air bubble ASD, and will be disposed in the recipient stream at substantially the same location as the auxiliary air bubble ASD is disposed in the donor stream. This is to say, the said auxiliary air bubbles will be in substantially perfect phase relationship.

This same operation of valve means 38 will be effective to introduce an auxiliary air bubble ASD at the respective downstream and upstream sides of each of the blood serum sample portions 5,, S 8;, etc. as the same are pumped past the juncture of conduits 40 and 34. As each of the said auxiliary air bubbles ASD passes in donor stream conduit 34 through the transmission path of detector means 100, the same will be operable, through delay timer means 114, and after the expiration of a time period predetermined to enable the said auxiliary air bubble ASD to reach the location indicated at ASD -,to control valve 46 to introduce a correspondingly sized and located auxiliary air bubble ASR to the recipient stream in conduit 42.

Concomitant flow of the segmented donor stream, with the respective segmented blood serum sample portions thereof clearly delineated at both the downstream and upstream ends thereof by the auxiliary air bubbles ASD and the segmented recipient stream correspondingly delineated into respective recipient stream portions by the auxiliary air bubbles ASR, will then occur through the dialyzer means 50 to effect the desired blood sample constituent dialysis. More specifically. and if it is assumed that colorimeter 64 is arranged to colorimetrically analyze the respective and clearly delineated blood serum sample portions of the donor stream for the total protein constituent thereof and colorimeter 66 is arranged to colorimetrically analyze the respective correspondingly delineated portions of the recipient stream for the calcium constituent thereof, the concomitant flow of the respective donor and recipient streams through the dialyzer means 50 will result in the transfer, through the nonillustrated dialyzer means membrane, of the calcium constituent from the donor stream to the recipient stream, while the total protein constituent will remain in the said donor stream.

Upon the exit of the respective donor and recipient streams from the dialyzer means 50, the same would be successively suitably treated, as by the introduction of suitable colorproducing reagents thereto and the subsequent mixing or heating thereof-as determined by the particular constituents of interest in manners not specifically illustrated or described herein, but which are specifically illustrated and described in said U.S. Pat. No. 3,24l ,432to enable the suitable colorimetric analysis thereof for the said constituents. In addition, suitable donor stream treatment in the nature, for example, of incubation or dilution, may be required upstream of the dialyzer means 50 again depending upon the particular constituents of interest, and again in manners made clear in said US. Pat. No. 3,241,432.

Following such stream treatment, the donor stream will flow through conduit 58 to and through the debubbler means 56, while the recipient stream will flow through conduit 62 to and through the debubbler means 60. Upon entry to the debubbler means 56, the said donor stream will be constituted by the respective blood serum sample portions 5,, 8,, 8,, etc. as segmented by the intrasample air bubbles AS and as separated by the auxiliary air bubbles ASD, the wash liquid segments W, as segmented by the intraportion air bubbles AW. Upon entry into debubbler means 62, the recipient stream will be constituted by the portions of the recipient stream liquid as separated, one from the other, by the auxiliary air bubbles ASR and as segmented by the intraportion air bubbles AR.

With regard to the flow of the donor stream through debubbler means 56, the gas removal capacity of the latter is predetermined to be sufficient to remove to atmosphere all of the intrasample air bubbles AS and all of the wash liquid segment air bubbles AW therefrom while removing a portion, only, of the auxiliary air bubbles ASD therefrom, whereby the donor stream which flows from the debubbler means 56 through conduit 76 to and through the flow cell 68 of colorimeter 64 will be constituted, as shown, by the continuous blood serum sample portions separated, each from the other, by the remaining portions of the auxiliary air bubbles ASD as separated by the recombined wash liquid segment W.

The total volume of the sight passage 72 of flow cell 68 is made less than the total volume of each of the continuous sample portions 8,, 8,, 8,, etc. whereby may be understood that a predetennined period of colorimetric analysis time will be provided during which the entire sight passage is filled, as depicted, with the said sample portion. It is, of course, during this period of time that the output of photoelectric detector means 82 will be fed, through stepping switching means 88, and along lead 96 to operate strip chart recorder means 90 to provide a permanent record of such colorimetric analysis on the recorder strip chart 98.

Of particular significance is the fact that an auxiliary air bubble ASD will be flowed through the flow cell 68 immediately prior to and immediately after the flow of each of said sample portions therethrough, and that the cleansing effect of this auxiliary air bubble flow, as enhanced by the flow of the wash liquid segment W through the said flow cell, will be effective to cleanse the flow cell 68 to the extent that contamination of successive sample portions will be substantially prevented to ensure the accuracy of the colorimetric analyses of all of said sample portions.

With regard to the flow of the recipient stream through debubbler means 60, it may be understood that the gas removal capacity of the latter is predetermined to be sufficient to remove to atmosphere all of the air bubbles AR while removing a portion, only, of the auxiliary air bubbles ASR therefrom. Accordingly, the recipient stream which flows from the debubbler means 60 through conduit 78 to and through the flow cell 70 of colorimeter 66 will be constituted, as shown, by the continuous recipient stream portions RD containing the dialyzed constituent of interest and separated, each from the other, by the remaining portions of the auxiliary air bubbles ASR, as separated by the substantially pure segments of the recipient stream R which passed through the dialyzer means 50 concomitantly with the wash liquid segments W and the air bubbles AW.

As described hereinabove with regard to the volume of sight passage 72 of flow cell 68, the total volume of sight passage 74 of flow cell 70 is made less than the total volume of each of the continuous recipient stream portions RD, whereby the depicted flow cell condition will, of necessity, occur to enable meaningful colorimetric analyses of the RD portions.

Again of particular significance, however, is the fact that an auxiliary air bubble ASR will be flowed through the flow cell 70 immediately prior to and after the flow of each of said continuous recipient stream portions RD therethrough, and that the cleansing effect of this auxiliary air bubble flow, as enhanced by the flow of the substantially pure recipient stream portion R through the said flow cell, will be effective to cleanse the flow cell 70 to the extent that contamination of successive recipient stream portions RD will be substantially prevented to ensure the accuracy of the colorimetric analyses of all of said recipient stream portions RD.

To make clear the extreme significance of providing for air bubble flow through the flow cell of fluid sample analysis means of the nature disclosed, a minimum time period in the order of l8 seconds would be required to suitably cleanse each of the flow cells of the low sample volume and flow rate, and high analysis rate, as discussed hereinabove, in the absence of the flow of at least one air bubble therethrough between adjacent discrete fluid portions to be colorimetrically analyzed, and that this cleansing time period would be required despite the provision of a suitable wash liquid segment therebetween. With the passage of at least one intersam ple portion air bubble through the said flow cell, it has been determined that this requisite flow cell cleansing time can be reduced to less than 2 seconds. Accordingly, and since as discussed hereinabove, the total analysis time available for each of said discrete fluid samples is only 12 seconds, it may be readily understood that operation of such analysis means at the desired 300 fluid sample per hour rate would be rendered impossible in the absence of as yet, undeveloped means to accomplish this essential intersample flow cell cleansing in the time available which is, of course, much less than l2 seconds, without the flow of an intersample or auxiliary air bubble therethrough.

Of additional significance and advantage with regard to the passage of auxiliary air bubbles through the analysis means flow cells 68 and 70 is the fact that the same will provide for the clear delineation on the recorder strip chart 98 of the successively recorded results of the colorimetric analyses of the respective sample and recipient stream portions. Since an auxiliary air bubble both immediately precedes and follows the flow of each of said stream portions and since the light transmission characteristics of air are substantially difierent than those of the liquids ofinterest, passage of the auxiliary air bubble through the flow cells 68 and 70 will result in the provision on the recorder strip chart 98 of clearly discernible indicia to mark the beginning and end of the passage of each of said stream portions through said flow cells.

Referring now to the form of the apparatus of the invention of FIG. 2, it may be understood that the operation thereof is substantially similar to that of the apparatus form of FIGS. 1A and 18 with the primary exception being that, in the former, the respective valve means 38 and 46 are operated simultaneously from the pump drive means 25 to simultaneously introduce the correspondingly sized auxiliary air bubbles ASD and ASR to the respective donor and recipient streams every time a leading or trailing edge of a sample portion arrives at the juncture of the conduit 40, and conduit 34. Accordingly, the subsequent advantageous results of the operations of the two apparatus forms will be substantially identical.

As between the two disclosed apparatus forms of the invention, the form of FIG. 2 offers the advantage of system simplicity in that detecting means 100, along with delay timer means 114, are eliminated therein. A problem which may, however, arise in the operation of the apparatus form of FIG. 2 resides in the fact that, although the respective auxiliary air bubbles ASD and ASR are simultaneously introduced at substantially corresponding locations in the respective donor and recipient stream conduits 34 and 42, the nature and/or extent of the conduits between these corresponding locations of auxiliary air bubble introduction and the respective entries thereof into the dialyzer means 50 may result in the degradation of the essential phase relationship between the auxiliary air bubbles, with the probably intolerable result that the essential phase relationship for the passage of the respective donor and recipient stream portions through the said dialyzer means will be likewise degraded.

Although specifically disclosed in conjunction with automatic blood analysis means, it is believed clear that the system of the invention would be equally applicable for use in like analysis means for the analysis of fluids other and different than blood serum samples. Too, although disclosed as operable to introduce air as the auxiliary separating fluid, it is believed clear that other separating fluids in the nature of other and different gases or liquids could be utilized, with ap propriate change in the nature and/or manner of operation of the detecting means 100. T00, and even for use with air or other gases as the separating fluid, it may be understood that other and different detecting means in the nature, for exam ple, of electrical conductivity or light transmission sensitive means, could be utilized.

In addition, and for purposes of comprehensiveness of disclosure, the system of the invention has been disclosed for use in analysis systems wherein both the donor and recipient streams are colorimetrically analyzed, it may be understood that the invention system could equally well be utilized in analysis systems wherein the donor stream is flowed to waste upon exit from the dialyzer. Notwithstanding, the introduction of the auxiliary air bubbles ASD would provide the advantageous cleansing and discrete sample portion delineation functions during the flow thereof through the donor conduit and dialyzer means.

Further, and although disclosed in conjunction with fluid sample analysis means having only one fluid sample flow con duit, the system of the invention is applicable, through duplication of conduit 40 and possibly valve means 38, for use in fluid sample analysis means as discussed hereinabove wherein the aspirated fluid sample is divided into a plurality of fluid sample portions for flow in individual conduits immediately downstream of the peristaltic pump means 24.

Too, it is believed clear that the disclosed apparatus arrangement of the form of FIGS. 1A and 18 could be reversed with the valve-controlled conduit 40 being connected to recipient stream conduit 42 at a corresponding location therein and operative, under the control of the pump drive means 25, to periodically introduce an auxiliary air bubble ASR therein to delineate the segmented recipient stream into the stream portions R. in such event, the detecting means 100 rearranged to detect the flow of said auxiliary air bubbles ASR at a corresponding location in the said recipient stream conduit, while the valve-controlled conduit 48 is connected to donor stream conduit 34 at a corresponding location and is operative appropriately introduce the auxiliary air bubbles ASD thereto at the leading and trailing edge of the respective segmented sample portions 8,, S, S etc., in response to the detection of the appropriately phased auxiliary air bubbles ASR in the recipient stream conduit by the detecting means 100.

While we have shown and described the preferred embodiment of our invention, it will be understood that the invention may be embodied otherwise than as herein specifically illustrated or described, and that certain changes in the form and arrangement of parts and in the specific manner of practicing the invention may be made without departing from the underlying idea or principles of this invention within the scope of the appended claims.

1. Apparatus for the introduction of separating fluid to fluid sample analysis means comprising: means for directing a first liquid stream of successive samples along a fluid analysis flow path and a second liquid stream along a fluid analysis flow path, means for intermittently introducing a separating fluid portion into said fluid sample analysis means flow path and between successive ones of said samples in said first liquid stream, means for intermittently introducing another separating fluid portion into said another fluid sample analysis means flow path and into said second liquid stream, said separating fluid portion and said another separating fluid portion being immiscible with respect to said first and second liquid streams, respectively, said introducing means being operative to introduce said separating fluid portion and said another separating fluid portion into said first and second liquid streams, respectively, in particular phase relationship, such that said separating fluid portion and said another separating fluid portion flow through respective one of said fluid sample analysis means flow paths in said particular phase relationship.

2. ln apparatus as in claim 1 wherein, said separating fluid portion and said another separating fluid portion are of substantially the same extent in said fluid sample analysis means flow paths.

3. ln apparatus as in claim 1 wherein, said separating fluid portion and said another separating fluid portion are substantially concomitantly introduced into said fluid sample analysis means flow paths at substantially corresponding locations therein, whereby said separating fluid portion and said another separating fluid portion will be in substantial phase relationship.

4. In apparatus as in claim 1 wherein, said separating fluid portion and said another separating fluid portion are respectively introduced into said fluid sample analysis means flow paths at different locations therein, said means to introduce another separating fluid portion being operatively associated with said another fluid sample analysis means flow path at location therein corresponding to a location in said fluid sample analysis means flow path which is downstream of the location at which said separating fluid portion is introduced thereto, and said means to introduce said another separating fluid portion being operable only when said separating fluid portion has reached said downstream location in said fluid analysis means flow path, whereby said separating fluid portion and said another separating fluid portion will be in substantial phase relationship.

5. In apparatus as in claim 1 said fluid analysis means includes a flow cell having a sight passageway, and a part, at least, of at least one of said separating fluid portions is effective to flow through the sight passage of said fluid analysis means flow cell.

6. ln apparatus as in claim 4 wherein, said means to introduce said another separating fluid portion comprise means to detect the flow of said separating fluid portion in said fluid sample analysis means flow path, and means responsive to said detecting means to operate said means to introduce said another separating fluid portion.

7. In apparatus as in claim 6 wherein, said detecting means are operative to detect said separating fluid portion at a loca tion in said fluid sample analysis means flow path intermediate said portion introduction location and said downstream location, and said operating means comprise delay means which are operable to delay operation of said means to introduce said another separating fluid portion until said fluid separating portion has been flowed from said intermediate location to said downstream location.

8. In apparatus as in claim 2 wherein, said separating fluid portion and said another separating fluid portion are substantially concomitantly introduced into said fluid sample analysis means flow paths at substantially corresponding locations therein, whereby said separating fluid portion and said another separating fluid portion will be in substantial phase relationship.

9. ln apparatus as in claim 4 wherein, said separating fluid portion and said another separating fluid portion are of substantially the same extent in said fluid sample analysis means flow paths.

10. In apparatus as in claim 8 said fluid analysis means includes a flow cell having a sight passageway, and a part, at least, of at least one of said separating fluid portions is effective to flow through the sight passage of said fluid analysis means flow cell.

ll. ln apparatus as in claim 9 said fluid analysis means includes a flow cell having a sight passageway, and a part, at least, of at least one of said separating fluid portions is effective to flow through the sight passage of said fluid analysis means flow cell.

12. In apparatus as in claim 6 said fluid analysis means includes a flow cell having a sight passageway, and a part, at least, of at least one of said separating fluid portions is effective to flow through the sight passage of said fluid analysis means flow cell.

13. In apparatus as in claim 8 wherein said fluid sample analysis means comprise pump means and dialyzer means, said fluid sample analysis means flow path comprises a conduit connecting said pump means and the donor side of said dialyzer means, said another fluid sample analysis means flow path comprises another conduit connecting said pump means and the recipient side of said dialyzer means, said means to introduce said separating fluid portion comprise valve controlled conduit means connecting said pump means and one of said conduits at a location intermediate said pump means and said dialyzer means, and said means to introduce said another separating fluid portion comprise other valve controlled conduit means connecting said pump means and the other of said conduits at a corresponding location intermediate said pump means and said dialyzer means.

14. In apparatus as in claim 9 wherein said fluid sample analysis means comprise pump means and dialyzer means, said fluid sample analysis means flow path comprises a conduit connecting said pump means and the donor side of said dialyzer means, said another fluid sample analysis means flow path comprises another conduit connecting said pump means and the recipient side of said dialyzer means, said means to introduce said separating fluid portion comprise valve controlled conduit means connecting said pump means and one of said conduits at a location intermediate said pump means and said dialyzer means, and said means to introduce said another separating fluid portion comprise other valve controlled conduit means connecting said pump means and the other of said conduits at a location intermediate said pump means and said dialyzer means but closer to said dialyzer means than the connection location of said valve controlled conduit means.

15. In apparatus as in claim 1 wherein, said fluid sample analysis means are operative to flow a stream of successive portions of different fluid samples through said fluid analysis means flow path, and said means to introduce said separating fluid portion into said flow path are operative to introduce the same thereinto substantially at the beginning and end of each of said different fluid sample portions during the flow of the latter therethrough.

16. In apparatus as in claim 8 wherein, said fluid sample analysis means are operative to flow a stream of successive portions of different fluid samples through said fluid analysis means flow path, and said means to introduce said separating fluid portion into said flow path are operative to introduce the same thereinto substantially at the beginning and end of each of said different fluid sample portions during the flow of the latter therethrouph. I

17. A method or introducing a separating fluid to fluid sample analysis means, the steps of, intermittently introducing a separating fluid portion into a fluid sample analysis means flow path directing a first liquid stream of successive samples, so as to be disposed between successive ones of said samples, intermittently introducing another fluid sample analysis means flow path directing a second liquid stream and in particular phase relationship with said separating fluid portion introduced between successive samples in said first liquid stream, said separating fluid portion and said another separating fluid portion being immiscible with respect to said first and second liquid streams, respectively.

18. In a method as in claim l7 wherein, said separating fluid portion and said another separating fluid portion are introduced into said fluid sample analysis means flow paths in such manner as to be ofsubstantially the same extent therein.

19. In a method as in claim 18 wherein, said separating fluid portion and said another separating fluid portion are substantially concomitantly introduced into said fluid sample analysis means flow paths at substantially corresponding locations therein, whereby said separating fluid portion and said another separating fluid portion will be in substantial phase relationship.

20. In a method as in claim 19 further comprising the steps of, detecting said separating fluid portion in said fluid analysis means flow path at a first location therein, delaying the introduction of said another separating fluid portion until said separating fluid portion has been flowed to a second location in said fluid sample analysis means flow path, and introducing said another separating fluid portion at a location in said another fluid sample analysis means flow path corresponding to said second location in said fluid analysis means flow path, whereby said separating fluid portion and said another separating fluid portion will be in substantial phase relationship.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 600, 953 Dated August 24, 1971 Inventor) Jack ISREELI, Aaron KASSEL and Richard H. HEIMANN It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 12, line 25, after "another" insert the following separating fluid portion into another Signed and sealed this 6th day of June 1972.

(SEAL) Attest:

EDWARD M.FLETCHER, JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents M PQ'1OSOHO'S9' USCOMM-DC scam-pe (1 U 5 GOVERNMENT PRINTING OFFICE 969 (-36533l 

1. Apparatus for the introduction of separating fluid to fluid sample analysis means comprising: means for directing a first liquid stream of successive samples along a fluid analysis flow path and a second liquid stream along a fLuid analysis flow path, means for intermittently introducing a separating fluid portion into said fluid sample analysis means flow path and between successive ones of said samples in said first liquid stream, means for intermittently introducing another separating fluid portion into said another fluid sample analysis means flow path and into said second liquid stream, said separating fluid portion and said another separating fluid portion being immiscible with respect to said first and second liquid streams, respectively, said introducing means being operative to introduce said separating fluid portion and said another separating fluid portion into said first and second liquid streams, respectively, in particular phase relationship, such that said separating fluid portion and said another separating fluid portion flow through respective one of said fluid sample analysis means flow paths in said particular phase relationship.
 2. In apparatus as in claim 1 wherein, said separating fluid portion and said another separating fluid portion are of substantially the same extent in said fluid sample analysis means flow paths.
 3. In apparatus as in claim 1 wherein, said separating fluid portion and said another separating fluid portion are substantially concomitantly introduced into said fluid sample analysis means flow paths at substantially corresponding locations therein, whereby said separating fluid portion and said another separating fluid portion will be in substantial phase relationship.
 4. In apparatus as in claim 1 wherein, said separating fluid portion and said another separating fluid portion are respectively introduced into said fluid sample analysis means flow paths at different locations therein, said means to introduce another separating fluid portion being operatively associated with said another fluid sample analysis means flow path at location therein corresponding to a location in said fluid sample analysis means flow path which is downstream of the location at which said separating fluid portion is introduced thereto, and said means to introduce said another separating fluid portion being operable only when said separating fluid portion has reached said downstream location in said fluid analysis means flow path, whereby said separating fluid portion and said another separating fluid portion will be in substantial phase relationship.
 5. In apparatus as in claim 1 said fluid analysis means includes a flow cell having a sight passageway, and a part, at least, of at least one of said separating fluid portions is effective to flow through the sight passage of said fluid analysis means flow cell.
 6. In apparatus as in claim 4 wherein, said means to introduce said another separating fluid portion comprise means to detect the flow of said separating fluid portion in said fluid sample analysis means flow path, and means responsive to said detecting means to operate said means to introduce said another separating fluid portion.
 7. In apparatus as in claim 6 wherein, said detecting means are operative to detect said separating fluid portion at a location in said fluid sample analysis means flow path intermediate said portion introduction location and said downstream location, and said operating means comprise delay means which are operable to delay operation of said means to introduce said another separating fluid portion until said fluid separating portion has been flowed from said intermediate location to said downstream location.
 8. In apparatus as in claim 2 wherein, said separating fluid portion and said another separating fluid portion are substantially concomitantly introduced into said fluid sample analysis means flow paths at substantially corresponding locations therein, whereby said separating fluid portion and said another separating fluid portion will be in substantial phase relationship.
 9. In apparatus as in claim 4 wherein, said separating fluid portion and said another separating fluid portion are of substantially the same extent in Said fluid sample analysis means flow paths.
 10. In apparatus as in claim 8 said fluid analysis means includes a flow cell having a sight passageway, and a part, at least, of at least one of said separating fluid portions is effective to flow through the sight passage of said fluid analysis means flow cell.
 11. In apparatus as in claim 9 said fluid analysis means includes a flow cell having a sight passageway, and a part, at least, of at least one of said separating fluid portions is effective to flow through the sight passage of said fluid analysis means flow cell.
 12. In apparatus as in claim 6 said fluid analysis means includes a flow cell having a sight passageway, and a part, at least, of at least one of said separating fluid portions is effective to flow through the sight passage of said fluid analysis means flow cell.
 13. In apparatus as in claim 8 wherein said fluid sample analysis means comprise pump means and dialyzer means, said fluid sample analysis means flow path comprises a conduit connecting said pump means and the donor side of said dialyzer means, said another fluid sample analysis means flow path comprises another conduit connecting said pump means and the recipient side of said dialyzer means, said means to introduce said separating fluid portion comprise valve controlled conduit means connecting said pump means and one of said conduits at a location intermediate said pump means and said dialyzer means, and said means to introduce said another separating fluid portion comprise other valve controlled conduit means connecting said pump means and the other of said conduits at a corresponding location intermediate said pump means and said dialyzer means.
 14. In apparatus as in claim 9 wherein said fluid sample analysis means comprise pump means and dialyzer means, said fluid sample analysis means flow path comprises a conduit connecting said pump means and the donor side of said dialyzer means, said another fluid sample analysis means flow path comprises another conduit connecting said pump means and the recipient side of said dialyzer means, said means to introduce said separating fluid portion comprise valve controlled conduit means connecting said pump means and one of said conduits at a location intermediate said pump means and said dialyzer means, and said means to introduce said another separating fluid portion comprise other valve controlled conduit means connecting said pump means and the other of said conduits at a location intermediate said pump means and said dialyzer means but closer to said dialyzer means than the connection location of said valve controlled conduit means.
 15. In apparatus as in claim 1 wherein, said fluid sample analysis means are operative to flow a stream of successive portions of different fluid samples through said fluid analysis means flow path, and said means to introduce said separating fluid portion into said flow path are operative to introduce the same thereinto substantially at the beginning and end of each of said different fluid sample portions during the flow of the latter therethrough.
 16. In apparatus as in claim 8 wherein, said fluid sample analysis means are operative to flow a stream of successive portions of different fluid samples through said fluid analysis means flow path, and said means to introduce said separating fluid portion into said flow path are operative to introduce the same thereinto substantially at the beginning and end of each of said different fluid sample portions during the flow of the latter therethrough.
 17. A method for introducing a separating fluid to fluid sample analysis means, the steps of, intermittently introducing a separating fluid portion into a fluid sample analysis means flow path directing a first liquid stream of successive samples, so as to be disposed between successive ones of said samples, intermittently introducing another fluid sample analysis means flow path directing a second liquid stream and in particular phase relationship with said separAting fluid portion introduced between successive samples in said first liquid stream, said separating fluid portion and said another separating fluid portion being immiscible with respect to said first and second liquid streams, respectively.
 18. In a method as in claim 17 wherein, said separating fluid portion and said another separating fluid portion are introduced into said fluid sample analysis means flow paths in such manner as to be of substantially the same extent therein.
 19. In a method as in claim 18 wherein, said separating fluid portion and said another separating fluid portion are substantially concomitantly introduced into said fluid sample analysis means flow paths at substantially corresponding locations therein, whereby said separating fluid portion and said another separating fluid portion will be in substantial phase relationship.
 20. In a method as in claim 19 further comprising the steps of, detecting said separating fluid portion in said fluid analysis means flow path at a first location therein, delaying the introduction of said another separating fluid portion until said separating fluid portion has been flowed to a second location in said fluid sample analysis means flow path, and introducing said another separating fluid portion at a location in said another fluid sample analysis means flow path corresponding to said second location in said fluid analysis means flow path, whereby said separating fluid portion and said another separating fluid portion will be in substantial phase relationship. 